1590s, from Late Latin entitatem (nominative entitas), from ens (genitive entis) "a thing," proposed by Caesar as present participle of esse "be" (see is), to render Greek philosophical term to on "that which is" (from neuter of present participle of einai "to be;" see essence). Originally abstract; concrete sense in English is from 1620s.

database In an entity-relationship model, an entity is a type of thing being modeled such as "person" or "product". Different entities have different sets of attributes such as "name" or "price" and are connected via relationships like "bought". Entities are closely related to classes (class). (2009-11-22)